> Web-Facing is simply a process of building/converting
> a Graphical User Interface (GUI) on top of a
> new or existing business application.

The term 'web-facing' and its ilk has been adopted by who knows how
many people as a generic term meaning 'uses a web UI.'  This is all
too often confused with the IBM product called WebFacing which is part
of WDSCi.  It reads the DDS source and creates Java servlets and jsp
pages for deployment on WAS or Tomcat.

JWalk is a screen scraper, which is a process of reading the 5250 data
stream and interpreting the look & feel based on what it sees.
Neither WebFacing nor JWalk change the underlying RPG programs which
make up the application, but at least WebFacing uses industry standard
Java to create its UI.

Why is this important?  With IBM's WebFacing, you can convert your
application once, and re-use the converted components (JSP, servlets,
classes) in your own design.  You've already deployed WAS and Apache
and have literally all the infrastructure you need to add brand new
servlets to the application.

With a screen scraper, you get none of that and you are 'locked in' to
their solution.  You can't incrementally add to your existing deployed
web code base because you haven't got any.  When you want to make a
change, you must go back to the DDS and make your changes there.
Modern screen scrapers all have some way to customise the look of a
screen, which often means that once you've changed the DDS you have to
revisit the 'customiser' and make the GUI panel look good again.

What to choose?  It all boils down to the reason you are contemplating
a web UI.  If you don't want to pay for a leased line and want the new
office in Guatemala to access your app via a browser, you have a
different set of criteria and problems than if you are trying to use
Java because it meshes with the corporate goal of interoperability
with some other vendor's application, which in turn is a different
problem than being an ISV who needs the cachet of a web based product
in order to make sales.

In general, the screen scrapers are very easy to use and deploy, but
they have quirks in their recognition engines which are 'customised'
so the panels look good.  There's often a double maintenance penalty
(DDS and customiser) but since everybody knows DDS already it isn't
seen as that big a deal.  Scrapers often don't need source code, and
handle IBM panels like WRKSPLF.

The re-facing crowd often require source, and often make changes to
it.  Almost invariably, those changes can be reused to enhance the
application in the future.  Because they use source, they don't have
to make a guess about what the panel should look like, and thus have
fewer glitches in the recognition engine.

If your company wants to go to the web in a real way (learn Java,
learn web infrastructure, good change management) then choose one of
the re-facing products (PSC or WebFacing come to mind).  If you aren't
going to invest the effort in becoming web experts, then choose a
scraper (JWalk, Newlook and I think aXes fall into this category.)
  --buck




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